Mysterious faults quake brakes may hold secret to stopping tremors: Study

They can have their quake and beat it too.Researchers have identified the mechanism behind hidden underwater “brake zones” that stop earthquakes in their tracks, per a groundbreaking study published in the journal Science.“We’ve known these barriers existed for a long time, but the question has always been, what are they made of, and why do they keep stopping earthquakes so reliably, cycle after cycle?” said head author Jianhua Gong, Assistant Professor of Earth and Atmospheric Sciences in the College of Arts and Sciences at Indiana University Bloomington.The researcher was referring to the Gofar fault, a seafloor fracture located 1,000 miles off Ecuador in the Pacific Ocean that has been producing nearly-identical earthquakes at regular intervals over the last three decades.During this time frame, magnitude six tremors have occurred in the same spots every five to six years — a statistically significant consistency.This phenomenon eluded scientists until recently, when they discovered the mechanism behind these buffer zones — seawater and rocks that work together to nip earthquakes in the bud.To get to the bottom of the brake zones, Gong and other researchers analyzed data from two major ocean-floor experiments: one conducted in 2008 and another that ran from 2019 to 2022.During these tests, scientists had affixed special seismometers to the sea floor on two separate parts of the Gofar fault.These picked up thousands of tiny earthquakes in the weeks and months on either side of of the faults two magnitude six ruptures, allowing them to understand how the fault behaves before and after major ruptures.

They found that both the brake zones displayed intense tremor activity in the period preceding the earthquake, but then fell silent immediately after the subterranean shakefest.That’s because, as the researchers found, the barriers aren’t stationary rock structures but rather intricate regions where the fault fans out into multiple branches, formi...